Tank venting diagnostics (OBDII)

Fig 1: Identifying Tank Venting Diagnostics (OBD II)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Identifying Trionic Connected To Main Instrument Unit Pin 18 (K22)

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Trionic is connected to main instrument unit pin 18 (K22). If leakage is detected in the tank venting system by engine management system diagnostics, the lead to pin 18 (K22) will be grounded and the main instrument unit will send the information "Tighten fuel filler cap ON" out on the bus. The SID unit then displays the requested message.